Sort LDAP user list

fixes #7693

library/Icinga/Protocol/Ldap/Connection.php

@@ -442,7 +442,7 @@ class Connection
             ldap_control_paged_result($this->ds, 0);
         }
 
-        return $entries; // TODO(7693): Sort entries post-processed
+        return $entries;
     }
 
     protected function cleanupAttributes($attrs)

modules/setup/application/forms/AdminAccountPage.php

@@ -309,7 +309,9 @@ class AdminAccountPage extends Form
         }
 
         try {
-            return $backend->listUsers();
+            $users = $backend->listUsers();
+            natsort ($users);
+            return $users;
         } catch (Exception $e) {
             // No need to handle anything special here. Error means no users found.
             return array();